Catalytic dehydrogenation process

ABSTRACT

Dehydrogenatable organic compounds, diluted with steam, are dehydrogenated in the absence of free oxygen at high conversion and selectivity to less saturated compounds with a catalyst composite consisting essentially of one or more metals selected from the group consisting of Ni, Pd, Pt, Ir and Os in association with tin and a metal selected from the group consisting of cesium, rubidium, thallium and cerium deposited on a support such as alumina, silica or a Group II aluminate spinel.

United States Patent [1 1 Drehman July 8,1975

[ CATALYTIC DEHYDROGENATION PROCESS [75] Inventor: Lewis E. Drehman,Bartlesville,

Okla.

[22] Filed: Nov. 15, 1973 [21] Appl. No.: 415,944

[56] References Cited UNITED STATES PATENTS 6/1971 Rausch 260/669 2/1972Box et a1 260/680 R 3,674,706 7/1972 Box at al..... 252/412 3,682,8388/1972 Bloch 252/464 3,686,340 8/1972 Patrick et al... 260/672 R3,755,481 8/1973 Hayes 260/668 D Primary ExaminerPaul M. Coughlan, Jr.

[5 7] ABSTRACT Dehydrogenatable organic compounds, diluted with steam,are dehydrogenated in the absence of free oxygen at high conversion andselectivity to less saturated compounds with a catalyst compositeconsisting essentially of one or more metals selected from the groupconsisting of Ni, Pd, Pt, Ir and Os in association with tin and a metalselected from the group consisting of cesium, rubidium, thallium andcerium deposited on a support such as alumina, silica or a Group IIaluminate spinel.

3 Claims, N0 Drawings CATALYTIC DEI-IYDROGENATION PROCESS This inventionrelates to the catalytic dehydrogenation of organic compounds. In oneaspect, it relates to I dehydrogenation processes. In another aspect, itrelates to dehydrogenation catalysts.

The dehydrogenation of organic compounds is well known. Whilenoncatalytic thermal dehydrogenation of organic compounds is known, theuse of such methods is limited because of the extensive undesirable sidereactions which take place. Thus, a great number of catalytic processeshave been developed in order to minimize side reaction activity andimprove conversion and selectivity to desired products. Materials whichhave been proposed as dehydrogenation catalytic agents include GroupVIII metals and metal compounds reducible to the metal, e.g. noble metalcompounds. Generally, such catalytic agents as the Group VIII metalcompoundds have been proposed in combination or association with acarrier or support material such as alumina, silica, and the like. TheGroup VIII metal compound-containing catalytic agents are characterizedby high dehydrogenation activity and selectivity. Such materials,however, are subject to deactivation, particularly by coke laydown, andcan lose their activity very quickly, e.g., in a matter of minutes.Hence, although the selectivity and activity of the Group VIII metal,particularly the noble metal, catalytic agents in dehydrogenationprocesses is excellent, the cost of such agents in relation to theircatalytic activity and the need for frequent regeneration has inhibitedtheir acceptance in commercial dehydrogenation applications.

It is also known that the activity and useful life of Group VIIImetal-containing catalysts can be increased and extended byincorporating tin into such catalysts. Such catalysts, while overcomingto some extent some of the drawbacks of the Group VIII metal-containingcatalysts per se, still exhibit some deficiencies. For example,platinum/tin/zinc aluminate catalysts are highly active and selectivefor dehydrogenation and dehydrocyclization of paraffins. However, theylose activity during use and require regeneration at periodic intervals,depending upon the feed used. It is highly desirable to decrease, oreven eliminate, the need for regeneration.

It is, therefore, an object of this invention to provide an improveddehydrogenation process.

It is an object of this invention to provide improved dehydrogenationcatalyst systems.

Other aspects, objects and advantages will become apparent to thoseskilled in the art upon consideration of the following disclosure.

In accordance with this invention, it has been discovered that theactivity and stability of tin-promoted nickel-, palladium-, platinum-,iridiumand osmiumcontaining catalysts are unexpectedly improved bymodifying such catalysts with a metal selected from the group consistingof rubidium, cesium, cerium and thallium and their'compounds.

The finished catalyst compositions are useful in dehydrogenationprocesses wherein a steam-diluted dehydrogenation hydrocarbon iscontacted with such catalysts in the vapor phase in the substantialabsence of free oxygen.

The novel catalysts of this invention consist essentially of at leastone Group VIII metal selected from the group consisting of nickel,platinum, palladium, iridium and osmium, or a compound of such metalcapable of reduction, in combination with tin and a co-promoting metalselected from the group consisting of cesium, rubidium, thallium andcerium. The Group VIII metals include nickel, palladium, platinum,iridium and osmium, including compounds of such metals which are capableof reduction, e.g., platinic chloride, chloroplatinic acid, ammoniumchloroplatinate and the like and various coordination compounds such asplatinum diammine oxalate, platinum hexammine dihydroxide and the like,and mixtures thereof. The Group VIII metal content of the catalysts isin the approximate range of 0.1 to 5 weight percent'of the finalcatalyst.

In addition to the Group VIII metals, the catalyst composition containstin as a first co-promoter metal. The amount of tin is in theapproximate range of 0.01 to 5 weight percent of the final catalyst. Thetin component can be deposited with the primary metalcomponent upon thecatalytic carrier of the invention, separately or together by any mannerknown in the art such as by deposition from aqueous and non-aqueoussolutions of tin halides, nitrates, oxalates, acetates, oxides,hydroxides and the like.

In addition to the Group VIII metal and tin, the catalyst compositioncontains a second co-promoter metal or metal compound which is selectedfrom at least one of cesium, rubidium, thallium or cerium or mixturesthereof. The amount of the second co-promoter metal is in theapproximate range of 0.1 to 5 weight percent of the final catalyst.Suitable rubidium and cesium compounds include the oxides, hydroxides,oxalates, alkoxides, bicarbonates, carbonates, tartrates and the like.Suitable thallium compounds include the acetates, carbonates, chlorides,hydroxides, nitrates, sulfates and the like. Suitable cerium compoundsinclude the acetates, carbonates, hydroxides, nitrates, sulfates, andthe like.

In a preferred embodiment the amount of Group VIII metal, as definedabove, is in the approximate range of 0.1-1 weight percent, the amountof tin is in the approximate range of 0.1-2 weight percent and theamount of co-promoter metal is in the approximate range of 0.1-2 weightpercent, all weight percents based upon the weight of final catalyst.

The molar ratio of the Group VIII metal to tin can be in the range of10:1 to 1:10. The molar ratio of the Group VIII metal to the secondco-promoter can be in the range of 10:1 to 1:10. In a preferredembodiment the Group VIII metal to tin ratio is in the approximate rangeof 2:1 to 1:5 and the Group VIII metal to second co-promoter ratio is inthe approximate range of 2:1 to 1:3. In a more preferred embodiment theGroup VIII metal to tin ratio is about 1:3 and the Group VIII metal tosecond co-promoter ratio is about 1:1.

The carrier material which is employed in the preparation of thecatalyst of this invention include alumina, silica, magnesia, zirconia,alumino-silicates, Group II aluminate spinels and mixtures thereof. In apreferred embodiment the support material is a Group II aluminatespinel, particularly zinc aluminate spinel.

The catalytic materials of this invention can be prepared by any meansknown in the art, e.g., by coprecipitation with the support-material, byimpregnationof the supportmaterial, by mixing dry powders, by mixingaqueous and non-aqueous slurries and pastes with the support and thelike.

During the dehydrogenation reaction, the catalyst, which can be in anysuitable form such as granules, pills, pellets, spheres, and the like,will slowly lose some activity and will periodically require aregeneration by conventional means. In one regeneration method, thefeedstock is cut off and the catalyst is treated with steam-diluted airsuch that the oxygen content of the mixture is about 1-5 mol percent.The regeneration treatment can be carried out at temperatures andpressures within the dehydrogenation operating range for about to 60minutes.

The catalytic dehydrogenation processes of this invention are effectedat temperatures within the range of about 750 to about 1,200F,preferably in the range of l,000 to 1,100F, with the exact conditionsbeing dependent upon the feedstock and product desired. Pressures aregenerally in the range of about 0 to 500 p.s.i.g., and the spacevelocity is within the range of 200 to 10,000 volumes of feedstock pervolume of catalyst per hour (GHSV). The reactions of the invention arecarried out in the vapor phase in the presence of steam and in theabsence of oxygen at molar ratios of steam to organic feedstock in therange of 2-30zl, preferably 4-l0:l.

The processes of this invention are particularly well suited for thedehydrogenation of various dehydrogenatable organic compounds containingat least one grouping, i.e., adjacent C atoms singly bonded to eachother and each attached to at least one hydrogen atom. In addition tocarbon and hydrogen, these compounds can also contain nitrogen. Suchcompounds can contain from 2 to 12 carbon atoms. Among the classes oforganic compounds which can be treated according to the processes ofthis invention are alkanes, cycloalkanes, alkyl aromatic compounds,alkenes, alkylsubstituted pyridines and the like. The catalyst composition of this invention is particularly effective for thedehydrogenation of paraffins having from 2 to 12 carbon atoms.

The catalysts of this invention employing cesium, rubidium and thalliumas co-promoters are particularly effective in processes using a fixedbed catalytic reactor. The catalysts of this invention employing ceriumas co-promoter are particularly effective in moving bed dehydrogenationprocesses.

The following examples illustrate the invention.

EXAMPLE I Tin-Containing Support A slurry consisting of distilled water,finely divided alumina, finely divided reagent grade zinc oxide andfinely divided reagent stannic oxide was ball milled for one hour toobtain an intimate mixture. The slurry was dried overnight at 200220F ina forced draft oven. The resulting dry cake was crushed, sieved toremove coarse particles and the powder was compounded with 8 weightpercent of a polyethylene lubricant. The mixture was formed into /s-inchpellets and calcined in air in a muffle furnace which was programmed asfollows: 2 hours at 800F, 2 hours at 1,100F and 3 hours at l,850F. Aftercooling, the calcined pellets were crushed and sieved to obtain 16-20mesh particles. The thus prepared tin-containing support had a surfacearea of 12.0 square meters per gram, a pore volume of 0.33 cc per gramand an apparent bulk density of 0.96 gram per cc. The support contained39 weight percent zinc, 26.8 weight percent aluminum, 1.0 weight percenttin and 33.2 weight percent combined oxygen.

EXAMPLE 11 Preparation of Catalyst Catalyst A: A portion of thetin-containing catalyst support of Example 1 was impregnated withplatinum from an aqueous solution of chloroplatinic acid to form acatalyst composition containing 0.6 weight percent platinum based on theweight of the final catalyst. The mixture was dried 3 hours at 230F andcalcined 3 hours at l F.

Catalyst B:A portion of the tin-containing catalyst support of Example 1was impregnated with sodium from an aqueous solution of sodium carbonateto form a catalyst composition containing 0.07 weight percent of sodiumbased on the weight of the final catalyst. The mixture was dried, thenimpregnated with an aqueous solution of chloroplatinic acid sufficientto give 0.6 weight percent platinum based on the weight of the finalcatalyst. This mixture was dried 1 hour at 230F and calcined 3 hours at1050F.

Catalyst C:A portion of the tin-containing catalyst support of Example 1was impregnated with rubidium from an aqueous solution of rubidiumcarbonate to form a catalyst composition containing 0.35 weight percentof rubidium based on the weight of the final catalyst. The mixture wasdried, then impregnated with an aqueous solution of chloroplatinic acidsufficient to give 0.6 weight percent platinum based on the weight ofthe final catalyst. The mixture was dried 1 hour at 230F and calcined 3hours at 1,050F.

Catalysts D-l-l: Catalysts D-H were prepared by indi viduallyimpregnating portions of the tin-containing support of Example 1 with anaqueous solution of cesium carbonate sufficient to give the weightpercent of cesium shown in Table 1. After drying, each mixture wasfurther impregnated with an aqueous solution of chloroplatinic acidsufficient to give 0.6 weight percent platinum based on the weight ofthe final catalyst. Each mixture was dried 1 hour at 230F and calcined 3hours at 1,050F.

Catalyst 1: A portion of the tin-containing catalyst support of Example1 was impregnated with cerium and platinum from an aqueous solution ofcerous nitrate and chloroplatinic acid sufficient to give 0.43 weightpercent cerium and 0.6 percent platinum based on the weight of the finalcatalyst. The mixture was dried 1 hour at 220F and calcined 3 hours at1,050F.

Catalyst J: A portion of the tin-containing catalyst support of Example1 was impregnated with boron and platinum from an aqueous solution ofboric acid and chloroplatinic acid sufficient to give 0.04 weightpercent of boron and 0.6 weight percent platinum based on the weight ofthe final catalyst. The mixture was dried 1 hour at 230F and calcined 3hours at 1,050F.

Catalyst K: A portion of the tin-containing catalyst support of Example1 was impregnated with thallium from an aqueous solution of thalloussulfate sufficient to give 0.6 weight percent thallium based on theweight of the final catalyst. The mixture was dried, then impregnatedwith platinum from an aqueous solution of chloroplatinic acid sufficientto give 0.6 weight percent platinum based on the weight of the finalcatalyst. The mixture was dried 1 hour at 230F and calcined 3 hours at1050F.

Catalyst L: A slurry consisting of distilled water, finely dividedalumina and finely divided reagent grade zinc oxide was ball milled for1 hour to obtain intimate mixture. The slurry was dried overnight at200-220F in a forced draft oven. The resulting dry cake was crushed,sieved to remove coarse particles and the powder was compounded with 8weight percent of a polyethylene lubricant. The mixture was formed into/s-inch pellets and calcined in air in a muffle furnace which wasprogrammed as follows: 2 hours at 800F, 2

hours at l 100F and 3 hours at 1850F. After cooling, the calcinedpellets were crushed and sieved to obtain 16-20 mesh particles. The thusprepared support had a surface area of 12.0 square meters per gram, apore volume of 0.33 cc per gram and an apparent bulk density of 0.96gram per cc. The support contained 27.1 weight percent aluminum, 39.3weight percent zinc and 33.6 weight percent combined oxygen. The supportwas impregnated with an aqueous solution of cesium carbonate sufficientto give 0.41 weight percent of cesium based on the weight of the finalcatalyst and the mixture was dried. The mixture was then impregnatedwith an aqueous solution of chloroplatinic acid suffi- EXAMPLE [[1Dehydrogenation runs were conductedto determine the effects of Na. Rband Cs as co-promoters for the Pt/Sn reference catalyst A. n-Butane wasdehydrogenated at l 100F and 100 p.s.i.g. in the presence of 9l0 mols ofsteam per mol of n-butane and in the substantial absence of free oxygen.In each run. 1.4 cc of catalyst was used. The processes were conductedin a cyclic, continuous flow manner with an intermediate airregeneration of the catalyst. Each cycle consisted of a dehydrogenationstep of- 1 1.5 hours at the recited conditions, followed by a catalystregeneration step of minutes effected at process conditions.Regeneration was accomplished by shutting off the feed withoutdisturbing the steam injection rate for 5 minutes, then admittingsufficient air with the steam to provide about 2 mol percent of oxygenfor 20 minutes, followed by an other 5-minute purge with steam only. Theresults shown in Table I are the average of at least 3 such cycles.

The reactor effluent was analyzed by means of gasliquid chromatographyat the times indicated. Total conversion of the n-butane feed is interms of mole percent. Selectivity is given in terms of the percentageof total products formed converted into butenes and butadiene. Resultsare given in Table 1.

In each of the runs given in Table l the mo] ratio of SnzPt is 2.74:1.

Table 1 Run No. l 2 3 4 5 6 7 8 Catalyst A B C D E F G H Co-PromoterMetal none Na Rb Cs Cs Cs Cs Cs weight percent 0.07 0.35 0.25 0.5 0.50.75 1.0

mol/mol Pt 0.99 1.33 0.61 1.22 1.22 1.83 2.44 n-Butane, GHSV 7070 63006500 6280 6620 6420 6220 6340 1 Hour on stream conversion. 7r 32.5 34.236.0 37.3 38.2 36.5 26.9 24.0

selectivity. 7r 94.6 94.3 95.1 95.1 94.2 95.1 94.1 92.9

rate constant. K (a) 11,500 10.800 13.500 12,300 14,700 12.700 6540 54706 Hours on stream conversion, 92 21.3 22.9 27.2 23.5 31.9 29.0 20.1 18.3

selectivity. 92.2 92.6 94.5 93.7 93.7 94.2 92.6 91.7

k (b) 0.44 0.49 0.56 0.43 0.67 0.63 0.58 0.68 1 1 Hours on streamconversion. 71 15.0 16.9 22.9 16.4 27.2 24.9 18.0 16.1

selectivity. 7? 87.9 90.5 93.8 92.2 93.0 93.6 91.5 90.8

k 0.25 0.31 0.41 0.25 0.50 0.48 0.54 0.55 Rate of Decline in Activity.(c) /hr.

1-6 hours on stream 15.3 13.5 10.7 15.5 7.6 8.3 10.1 7.4

1-11 hours on stream 13.0 11.2 8.5 13.0 6.7 7.1 5.1 5.8 Coke Rate. in

mmol/hr. 0.49 0.21 0.15 0.39 0.63 0.16 0.24

*Not determined. (a) dehydrogenation rate constant. K

(GHSV) (conversion) (selectivity) (equilibrium conversion) (equilibriumconversion conversion selectivity) K at 6 or 11 hours (b) relative rateconstant k K at 1 hour (0) K (1-r)"", where r is the rate of decline andt is the number of hours on steam. (d) K at time zero. Determined fromcurves of K vs. time.

cient to give 0.6 weight percent of platinum based on the weight of thefinal catalyst. The mixture was dried 1 hour at 230F and calcined 3hours at 1050F.

The sodium co-promoted catalyst, B, shows a lesser activity decline,compared to the reference, but has lower initial activity. The rubidiumand cesium copromoted catalyst exhibit increased activity and slowerrate of deactivation as compared to both the reference catalyst and thesodium co-promoted catalyst.

The above data further illustrate that the optimum cesium level liesbetween 0.25 and 0.75 weight percent. The optimum level appears to benear 0.5 weight percent, which corresponds to a platinumzcesium molratio of about 1:1.

EXAMPLE 1V Runs were conducted to compare the effect of ceriumco-promoted catalyst with the reference catalyst. Results are given inTable II. The runs were conducted and effluents analyzed in the mannerof Example III. In each of these runs the mo] ratio Sn:Pt is 2.74: 1.

EXAMPLE V Dehydrogenation runs were conducted according to theprocedures set forth in Example 111 to compare catalysts A. J and K.Results of these runs are given in Table 111. In each of these runs themo] ratio Sn:Pt is 2.74:1.

Table 111 Run N0. 1 l 1 Catalyst A .1 K Co-Promoter Metal none B Tlweight percent 0.04 0.6 mol/mol Pt. 1.2 0.9 n-Butane. GHSV 7070 61806490 1 Hour on stream conversion. 70 32.5 35.8 38.6 selectivity. 94.691.0 95.0 K 1 1.500 10.600 14.400 6 Hours on stream conversion, 21.325.2 28.7 selectivity. 92.2 88.7 94.6 K 5000 5140 7500 1 1 Hours onstream conversion. 15.0 16.9 21.2 selectivity. 87.9 85.9 93.4 K 28502800 4600 k 0.25 0.26 0.32 Rate of Decline in Activity, %/hour 1-6 hourson stream 15.3 13.5 12.2 l-l 1 hours on stream 13.0 12.5 10.7 Coke rate.mmols/hr. 0.49 1.28 0.29

Table 11 Run No. l 9

Catalyst A 1 Co-Promoter Metal none Ce weight percent 0.43 mol/mol Pt1.0 n-Butane, GHSV 7070 6270 1 Hour on stream conversion. 32.5 40.4selectivity. 94.6 94.7 K 1 1.500 16.400 6 Hours on stream conversion,"/0 21.3 9.6 selectivity, 92.2 86.4 K 5000 1490 k 0.44 0.09 11 Hours onstream conversion. 7: 15.0 4.4 selectivity. 7: 87.9 74.0 K 2850 500 k0.25 0.03 Rate of decline in Activity. /r/hr. l-6 hours on stream 15.338.2 1-11 hours on stream 13.0 29.4 Coke rate. mmol/hr. 0.49 0.29 K14.500 60.000

The above data indicate that thallium is an effective co-promoter forthe basic catalyst, exhibiting a lesser rate of decline in activitytogether with better yield and selectivity. In contrast, boron, also aGroup Illa element. reduced the selectivity of the reference catalystand exhibited greatly increased formation of coke.

EXAMPLE V1 Table IV Run 1 12 5 6 Catalyst A L E F Pt, weight percent 0.60.6 0.6 0.6 Sn, weight percent 1.0 none 1.0 1.0

mol Sn/mol Pt 2.74 2.74 2.74 Promoter Metal none Cs Cs Cs weight percent0.41 0.5 0.5 mol/mol Pt. 1 1.22 1.22 n-Butane. GHSV 7070 6500 6620 64201 Hour on stream conversion 32.5 1 1.4 38.2 36.5 selectivity. 94.6 68.994.2 95.1 K 1 1.500 1730 14,700 12,700 6 Hours on stream conversion,21.3 7.0 31.9 29.0 selectivity. 92.2 58.8 93.7 94.2 K 5000 880 9900 7950k 0.44 0.51 0.67 O 1 1 Hours on stream conversion, 15.0 6.0 27.2 24.9selectivity, 87.9 58.3 93.0 93.6 K 2850 700 7320 6060 k 0.25 0.4 0.500.4 Rate of Decline in Activity, %/hr.

16 hours on stream 15.3 12.6 7.6 8.3 11 1 hours on stream 13.0 8.6 6.77.1 Coke rate, mmol/hr. 0.49 0.09 0.63 0.16

The above data illustrate that tin is a necessary component of thecatalyst system of this invention. ln the absence of tin, the values forconversion, selectivity and rate constants are drastically reducedcompared to reference catalyst A. Such values are also drasticallyreduced as compared to catalysts E and F which contained roughly similaramounts of cesium.

Reasonable variations and modifications are possible within the scope ofthis disclosure without departing from the scope and spirit thereof.

1 claim:

1. A process for the dehydrogenation of a dehydrogenatable organiccompound having from 2 to 12 carbon atoms per molecule in the presenceof steam and in the absence of free oxygen which comprises contactingsaid compound under dehydrogenation conditions with a catalystconsisting essentially of platinum, tin and cerium, each of saidplatinum, tin and cerium being supported on a support selected from thegroup consisting of alumina, silica, magnesia, zirconia,alumina-silicates, Group 11 aluminate spinels and mixtures thereof;

wherein said platinum is present in said catalyst in an amount rangingfrom about 0.1 to about 1 weight percent; said tin is present in anamount ranging from about 0.1 to about 2 weight percent; and said ceriumis present in an amount ranging from about 0.1 to about 2 weightpercent, all weight percents being based on the weight of finalcatalyst; and wherein the mole ratio of said platinum to said tin isabout 1:3 and the mole ratio of said platinum to said cerium is about1:1. 2. The process of claim 1 wherein said support is zinc aluminate.

3. The process of claim 2 wherein said organic compound is butane.

1. A PROCESS FOR THE DEHYDROGENATION OF A DEHYDROGENATABLE ORGANICCOMPOUND HAVING FROM 2 TO 12 CARBON ATOMS PER MOLECULE IN THE PRESENCEOF STEAM AND IN THE ABSENCE OF FREE OXYGEN WHICH COMPRISES CONTACTINGSAID COMPOUND UNDER DEHYDROGENATION CONDITIONS WITH A CATALYSTCONSISTING ESSENTIALLY OF PLATINUM,, TIN AND CERIUM, EACH OF SAIDPLATINUM, TIN AND CERIUM BEING SUPPORTED ON A SUPPORT SELECTED FROM THEGROUP CONSISTING OF ALUMINA, SILICA, MAGNESIA, ZIRCONIA,ALUMINA-SILICATES, GROUP II ALUMINATE SPINELS AND MIXTURES THEREOF,WHEREIN SAID PLATINUUM IS PRESENT IN SAID CATALYST IN AN AMOUNT RANGINGFROM ABOUT 0.1 TO ABOUT 1 WEIGHT PERCENT, SAID TIN IS PRESENT IN ANAMOUNT RANGING FROM ABOUT 0.1 TO ABOUT 2 WEIGHT PERCENT, AND SAID CERIUMIS PRESENT IN AN AMOUNT RANGING FROM ABOUT 0.1 TO ABOUT 2 WEIGHTPERCENT, ALL WEIGHT PERCENTS BEING BASED ON THE WEIGHT OF FINALCATALYST, AND WHEREIN THE MOLE RATIO OF SAID PLATINUM TO SAID TIN ISABOUT 1:3 AND THE MOLE RATIO OF SAID PLATINUM TO SAID CERIUM IS ABOUT1:1
 2. The process of claim 1 wherein said support is zinc aluminate. 3.The process of claim 2 wherein said organic compound is butane.